Conventionally, there is known a substrate liquid processing apparatus that performs a liquid process on a substrate such as a silicon wafer or a compound semiconductor wafer.
For example, there is known a substrate liquid processing apparatus in which a space for accommodating a gas exhaust pipe through which an exhaust gas from a liquid processing unit is flown is formed under the liquid processing unit (see Patent Document 1).
Patent Document 1: Japanese Patent Laid-open Publication No. 2008-034490
In the above-described prior art, however, there is still a room for improvement in that gas-liquid separation of the exhaust gas from the liquid processing unit can be improved.
For example, in the above-described prior art, a liquid drain cup and a gas exhaust cup are provided in the liquid processing unit, and it is attempted to improve the gas-liquid separation by performing the liquid draining from the liquid drain cup and the gas exhaust from the gas exhaust cup independently. However, there is still a concern that mist, for example, may be introduced into a gas exhaust path. Such introduction of the mist into the gas exhaust path is suppressed by providing a mist trap in the gas exhaust path, for example. However, it is still required to further suppress the introduction of the mist.